scholarly journals Modeling and Simulation of Heat Pump Air-Conditioning System using Ecofriendly Refrigerants

2021 ◽  
Vol 9 (VI) ◽  
pp. 1166-1170
Author(s):  
Ajay Landage
Keyword(s):  
Energy Efficiency ◽  
Comparative Analysis ◽  
Physical Properties ◽  
Heat Pump ◽  
Air Conditioning ◽  
Coefficient Of Performance ◽  
Simulation Approach ◽  
Alternative Refrigerants ◽  
Air Conditioning System ◽  
Selection Of

A simulation approach to heat pump systems is proposed in this paper. The evaluation of working fluids is conducted. Moreover, the selected refrigerants are used in the simulation. Subsequently, the system is analyzed in terms of the coefficient of performance (COP) and energy efficiency. Some alternative refrigerants, instead of R22 used R290 refrigerent. It is described the selection of refrigerants adapted to each utilization, based on the thermodynamic and -physical properties, the technological behaviour, costs and use constraints as principal aspects of the environmental protection. Also, it is performed a comparative analysis in function of the total equivalent warming impact (TEWI) for some possible substitutes of refrigerant R22 used in various refrigeration and heat pump systems.

Comparison and Selection of HVAC Schemes for Weihai Baidu City

2011 ◽  
Vol 374-377 ◽  
pp. 681-684
Author(s):  
Yan Peng Wu ◽  
Hai Shan Xia
Keyword(s):  
Energy Efficiency ◽  
Energy Saving ◽  
Heat Pump ◽  
Air Conditioning ◽  
Second Phase ◽  
Air Conditioning System ◽  
Air Source Heat Pump ◽  
Pipe Networks ◽  
Time Part ◽  
Selection Of

The second phase of Weihai Baidu City project plans to become a three-star certificated program which is labled by China’s enviromental building evaluation. Heating and ventilated air conditioning program is one of the most important aspects in evaluation of energy saving. Feasibility study on GSHP, GWHP, air-source heat pump, seawater source heat pump were carried out, it’s confirmed that the most energy-saving and reliable way is that using municipal pipe networks for heating in winter and using split air conditioning or multi-connected air-conditioning system in summer. Summer air-conditioning adopts the new idea “part of time, part of space", representative the latest concept of energy efficiency in buildings in China.

Experimental Study on Performance Enhancement of Heat Pump With Screw Compressor

2004 ◽  
Author(s):  
Wu Huagen ◽  
Shu Pengcheng ◽  
Zhao Yuanyang ◽  
Xing Ziwen
Keyword(s):  
Heat Pump ◽  
Air Conditioning ◽  
Performance Enhancement ◽  
Coefficient Of Performance ◽  
Screw Compressor ◽  
Alternative Refrigerants ◽  
Air Source Heat Pump ◽  
Central Air Conditioning ◽  
Compressor Performance ◽  
Industrial Refrigeration

The air-source heat pump has been widely used in industrial refrigeration and central air-conditioning applications because of its unique superiority. An important consideration in the design of heat pump is improving its COP (coefficient of performance). In this paper, the results of experimental investigation on the effects of alternative refrigerants (R22, R134a, R404A and R407C) and economizer on the performance of heat pump are presented. The COP of the heat pump used R134a is up to 4.5% higher than R22, but its capacity got a 37.08% decrease. The refrigerant R407C applied in heat pump can improve the capacity up to 7.86% than R22, but its COP shows a decrease up to 5.92%. The refrigerant R404A used in heat pump will result in poor capacity and COP compared to R22. The economizer system used in heat pump will improve the COP, but as the superfeed pressure of the economizer increases, the system COP increases first, and then drops. So there exists an optimal superfeed pressure of the economizer for the best COP. Also, the effect of the economizer on the screw compressor performance is analyzed by recording the P-v indicator diagram.

scholarly journals Exploratory Research to Improve Energy-Efficiency of a Ground-Coupled Heat Pump Utilizing an Automatic Control Device of Circulation Pump Speed

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5016
Author(s):  
Ioan Sarbu ◽  
Calin Sebarchievici
Keyword(s):  
Energy Efficiency ◽  
Simulation Model ◽  
Heat Pump ◽  
Co2 Emission ◽  
Air Conditioning ◽  
Coefficient Of Performance ◽  
Exploratory Research ◽  
Circulation Pump ◽  
Pump Speed ◽  
Heat Pump Unit

Ground-coupled heat pumps (GCHPs) are an efficient thermal energy production system that can satisfy the gap between heating and air-conditioning. Be that as it may, exploratory research on GCHPs is still lacking. The first objective of this article is to describe a utilitarian energy-efficiency improvement device for a vertical GCHP system that includes a buffer tank (BT) between the heat pump unit and the fan coil units and user supply, utilizing the quantitative regulation of water flow rate with a variable-speed circulation pump. At that point, the investigative estimations are utilized to test the performances of the GCHP system in various operating modes. Fundamental efficiency parameters (coefficient of performance (COP) and CO2 emission) are achieved for one month of running utilizing two control strategies of the GCHP—standard and optimized regulation of the water pump speed—and a benchmarking of these parameters is achieved. Exploratory research has indicated higher efficiency of the system for the flow regulation solution utilizing a BT and programmed control equipment for the circulation pump speed compared with the standard regulation solution (COPsys with 7–8% higher and CO2 emission level 7.5–8% lower). The second objective is to elaborate a simulation model of the necessary heat/cold in heating and air-conditioning periods, utilizing the Transient Systems Simulation (TRNSYS) program. Finally, the simulation, acquired utilizing the TRNSYS program, is analyzed and compared with experimental information, leading to a good agreement and, along these lines, the simulation model is approved.

Multiple Criteria Decision Method Used in Selection of Green Air-Conditioning System

2013 ◽  
Vol 732-733 ◽  
pp. 605-608
Author(s):  
Can Zhou ◽  
Yu Yun Li
Keyword(s):  
Heat Pump ◽  
Air Conditioning ◽  
Indoor Environment ◽  
Operating Costs ◽  
Structure Model ◽  
Air Conditioning System ◽  
Ground Source ◽  
Air Conditioning Systems ◽  
Operation And Management ◽  
Selection Of

Established a hierarchy structure model and made a quantitative assessment of seven air-conditioning systems which are gas boiler plus electric refrigerating system、air-cooled heat pump、variable refrigerant volume air conditioning、ground-source heat pump air conditioning、centralized heat-supply plus electric refrigerating、gas direct-fired machine、energy storage on relevant professionality and indoor environment,initial investment,operating costs,operation and management,environmental impact,energy consumption.Finally we obtained an optimal scheme,which agreed with that in practice.

Design and Performance of a Constant Temperature and Humidity Air-Conditioning System Driven by a Ground Source Heat Pump in Summer

2010 ◽  
Vol 2 (1) ◽  
Author(s):  
X. Yu ◽  
X. Q. Zhai ◽  
R. Z. Wang
Keyword(s):  
Heat Pump ◽  
Constant Temperature ◽  
Air Conditioning ◽  
Weather Condition ◽  
Coefficient Of Performance ◽  
Heat Extraction ◽  
Ground Source Heat Pump ◽  
Air Conditioning System ◽  
Ground Source ◽  
Temperature And Humidity

A constant temperature and humidity air-conditioning system driven by a ground source heat pump was designed and constructed in an archives building in Shanghai. The system consists of a water-to-water heat pump and 280 boreholes with 80 m in depth. During the operation in summer, the heat extraction from the condenser of the heat pump was divided: Part was rejected to the soil, while another was used to reheat the air in air handling units (AHUs). According to the experimental results under a typical summer weather condition of Shanghai, the average coefficient of performance of the heat pump was 5.4. The average indoor temperature and relative humidity of the archives house were 22.8°C and 46.6%, respectively. Since part of the heat extraction from the condenser was used to reheat the air in AHUs, the heat rejected to the soil was reduced by 23%, which was helpful for the earth energy conservation. According to the theoretical analysis, the distance between two boreholes is suggested to be 4–5 m. The deepness of the boreholes is suggested to be 80–100 m in Shanghai.

scholarly journals Performance investigation of a novel hybrid deep-dehumidification process using liquid desiccant

2019 ◽  
Vol 111 ◽  
pp. 01047
Author(s):  
Bowen Guan ◽  
Jun Liu ◽  
Xiaohua Liu ◽  
Tao Zhang ◽  
Liangliang Chen ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Heat Pump ◽  
System Performance ◽  
Air Conditioning ◽  
Cooling Capacity ◽  
Liquid Desiccant ◽  
Humidity Ratio ◽  
Air Conditioning System ◽  
Heating Capacity ◽  
Flow Through

As one of the essential dehumidification ways, liquid desiccant air conditioning system has developed quickly in recent years, especially in the deep dehumidification field. A novel hybrid deep- dehumidification system using liquid desiccant driven by heat pump is proposed in this study to simplify the arrangement of air ducts and guarantee a competitive energy efficiency. In the proposed process, the regenerator, condensing dehumidifier and liquid dehumidifier are cascaded, and the process air flow through them sequentially. Heat pump cycle is utilized in the system, where the cooling capacity of evaporator is used to cool the liquid desiccant in dehumidifier, and the heating capacity of condenser is used for desiccant regeneration. The humidity ratio of the supplied air is as low as 2.6 g/kg. No extra regeneration air or corresponding air duct are needed in the proposed process, which obviously simplifies the layout of the system. Performance of the proposed system is then analysed by numerical results. It’s indicated 17.5~29.2% energy is saved compared with the conventional deep dehumidification process with two-stage heat pump, with the outlet humidity ratio of 2.6 g/kg.

scholarly journals The modeling and energy efficiency analysis of thermal energy management operation of ground source heat pump air-conditioning system

2020 ◽  
Vol 24 (5 Part B) ◽  
pp. 3229-3237
Author(s):  
Xuli Wang ◽  
Jing Ma ◽  
Feng Zhao ◽  
Liang Tang ◽  
Lei Wang
Keyword(s):  
Energy Efficiency ◽  
Heat Pump ◽  
Air Conditioning ◽  
Hydraulic Loss ◽  
Ground Source Heat Pump ◽  
Efficiency Ratio ◽  
Air Conditioning System ◽  
Ground Source ◽  
Saving Effect ◽  
Management Operation

To improve the energy-saving effect of the ground source heat pump air-conditioning system, an example is investigated, and the annual loads of the building are simulated and analyzed. The thermal energy management operation modelling is conducted. The hydraulic analysis is performed for different modes in each section. Given the same flow and tube type, a larger pipe diameter indicates a smaller hydraulic loss. Compared with the parallel 5-well loop and the parallel 10-well loop, the hydraulic loss of the series 2-well loop is the highest. When the sub-catch is connected to 5 loops, as the number of series wells increases, the tube length gets longer, the flow rate allocated by the loop gets less, and the load increases. Besides, the energy efficiency ratio of the ground source side decreases as the heat rejection load increases. Therefore, by adjusting the pipe diameter, the pipe type, and the depth of the well, the hydraulic loss can be reduced. The energy-saving effect of the loop in the parallel mode is better. Given the limited number of the managed wells, the parallel circuit can be adjusted to the same program. The connection allows the collector to distribute the flow evenly. The energy efficiency ratio of the ground source can be improved by changing the diameter of the horizontal trunk pipe. It is hoped that the hydraulic optimization design of the ground source heat pump air-conditioning system can provide a theoretical basis for the application and promotion of the ground source heat pumps.

Calculation on Energy Saving Potential of a New Dry-Type Air-Conditioning System

2013 ◽  
Vol 756-759 ◽  
pp. 4388-4393
Author(s):  
Xiao Wei Hu ◽  
Yu Feng Zhang ◽  
Li Li Wei ◽  
Xin Hui Wu
Keyword(s):  
Energy Efficiency ◽  
Energy Saving ◽  
Heat Pump ◽  
Air Conditioning ◽  
Type System ◽  
Operating Conditions ◽  
Combined System ◽  
Air Conditioning System ◽  
Efficiency Comparison ◽  
Conventional Cooling

Temperature and humidity independent control can be made by a new dry-type air-conditioning system, the combination of silica gel rotor and heat pump. Heat pump cycle can simultaneously cool the process air and heat the regeneration air, so it can cancel each other out in the cold and heat energy consumption within the system. This novel form of system not only solves the regeneration energy issues fundamentally but also avoids energy waste by reheating in conventional cooling dehumidification air-conditioning system. Based on the establishment of the component model, MATLAB program has been compiled to simulate the combined system running at nominal operating conditions and calculate the performance parameters and energy efficiency. Comparison of the energy efficiency was made of this dry-type air-conditioning system with ones of other regeneration desiccant wheel air conditioning system and conventional cooling dehumidification air-conditioning system, the results of which show that the new dry-type system provided regeneration energy, overcomes the restriction from climate, region and using conditions of other regeneration. Moreover, compared with conventional re-heat air-conditioning system, its energy saving is up to 35.1% and the energy efficiency is increased by 38.1%.

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